Evolving CSMs in fractured rock: a case study of what we know (and what we think we know)

Characterisation and remediation in fractured rock settings has been recognised as technically challenging because fate and transport is complex (as compared to better understood fate and transport in typical soil and groundwater systems). Documented struggles to meet clean-up objectives and goals have meant that sites with fractured bedrock are often considered too difficult to successfully remediate. This abstract examines the conceptual site model (CSM) evolution that occurred over an approximate 8 year period (2011-2018) at a former aerosols manufacturing facility located above a fractured rock aquifer impacted by chlorinated volatile organic compounds. The site assessment and remediation challenges were evidenced by the iterative investigations carried out between 1992 and up to 2016 by various environmental consultants to address multiple uncertainties in the CSM. The CSM continued to be further refined between 2016 and 2018 during remediation works and also during site validation in 2019, indicative of the complex nature of the geological and hydrogeological setting. (author)